Apparatus for recovering gold and silver by use of cyanid solutions.



w. L. IMLM;4 APPARATUS OR RECOVERING GOLD AND SILVER BY' USE OF GYANID SOLUTIONS.

- APPLICATION FILED 12133.16, 1911. y 1,014,224 Patented Jan. 9, 1912.

SHEETS-SHEET l,

W. L. IMLAY.

APPARATUS POB RBOOVERINO GOLD ANO SILVER BY USE OF OYANID SOLUTIONS.

APPLICATION FILED PEB. 16, 1911. 1,014,224, Patented Ja11.9, 19.12.

2 SHEETS-SHEET 2.

I STATES PATENT onirica.

-WILLIAM L. IMLAY, F PHILADELPHIA, PENNSYLVANIA.'

APPARATUS FOR RECOVERING GOLD AND SILVERYBY USE 'OF CYNID SOLUTIONS.'

Specification of Letters Patent. Application led February 16A, 1911. Serial No. 609,603.

. Patented Jan. 9, 1912.

.To all 'li/'horn 'it may concern:

. Be itk known that I, WiLLIAM L. Imran?,`

a citizen of the United States, and residentof Philadelphia, county of Philadelphia,`

'10 for recovering gold and silver by use of cyanid solutions and consists of certain im# provements which vare fully set forth in the. following specificationl and shown in the ac.

companying drawings which form' a s part thereof.-

More particularly, my invention has for its object economy in the cost of recovery of the finer values of the ores,.`greater rapidity v ofthe recovery and less cost and space re- 20 quired the `equipment of Aa: cyanid plant.

In plants for recovery of gold and. silver by use of a solution of a cyanid of the alkalies, it'has been customary to treat the ores in a more or less pulver-ized condition to -a weak solution cyanid of potassium in a stamp battery, subject the pulp to hydraulic classification, regrind and concentrate the spigot product of 'the classifiers,- treatthe tailings from the concentrating tables and 39 vanners to further classifications to separate the sands from the slimes, treat the sands to a lengthy leaching in cyanid solution, treat the slimes to agitation, and decantation to obtain a clear cyanid 'solution' containing the" gold and silver values, 'subjecting the slimes to filtration to extract the cyanid solution containing the gold and silver values,

. and finally precipitate the gold and silver values by passing the clear cyanid solutions 49 through the zinc boxes in the usual manner. T hose steps are to ysome extent varied or modified to suit the character of the ores, in some cases providing foramalgamation with or without concentration. 1 Y

In employing my improvements in al cyanid plant, it is my object'to 4greatly re' duce the time required in leachingthe ores land to` eliminate much of the*extensive,apparatus heretfore employed in that department.

In 'a plant employing my-"invntifom'tle' preliminary treatment. of theores may follow the most approved null practice to suit the particular character ofthe ore, butafter 4 55 the said treatment, whether it be pulver- Ibe, ,to amalgamation or otherwise, the ore in may be drained and passed to the tailings 'izing l'in the -stamp battery with or without cyanid of potassium solution, and followed by treating the pulp or ore, as the case may the condition ofpulverization guaranteed by the screen mesh employed vw1th the stamp battery, isi-either reground `and fed', lor dil rectly fed, with cyanid of'potassium solution into my improved lixiviat-ing apparatus (hereinafter fully'described) in which it is subjected to a thoroughlixiviation with agitation and. aeration in a continuous manner andina limited, space, considering the actual time of treat-ment. .From the said lixiviat'ing treatmentthe slimes are separated .from the sands or tailings and transferred to the slimes department for precipitation of the values' ontained -therein and the sands dump without further cyaniding treatment 75- (unless otherwise desired from the special nature of the ores).

By use of my invention, it is not necessary to employ the;n expensive hydraulic classification equipments heretofore used, 80

.nor the usual' costly leaching outfits.. It is further to be pointed-outthat I am enabled to dispense, with ailarge proportion of the cyanid solution vats or tanks heretofore required, as,"by my invention, greatly less working volumes of cyanid solution are required for the' extraction 'of the values from the ores and .hencejless containers therefor 1' are necessary.

My invention more particularly consists in the employment'at some point, between the stamp battery and. the slimes department, of the lixiviating apparatus embody-v ing my improvements, the said\ apparatus comprising a slowly rotating-cylinder having one end arranged for receiving the pulverized ore and cyanid solution and the otherend arranged for the automatic de- Alivery of.- the pulp containing the slimes, .sands andsolution, the said cylinder havingup'onits' interior wall a helical inwardly extending flange4 supplementedby a plurality' 'of4 longitudinal inwardly directed ribs orf'buclet,structures5which operate, dur- A ing its rotation, to slowly convey the con- 95 ten fromthe feeding to the discharge end f t ecylinde'r and at the same time to carry up the-pulp and spill it downward through the airwith'resulting splash, thereby subjecting the pulp and cyanid solution to agi- 11@ I tation and aeration and thereby producing leaching so effectively that the finer values are dissolved out of the pulp with great rapidity.

My invention also comprehends details of.

Vline y-Jy of Fig. 21 Fig. 5 is an edge view., of one part of the, helical fiange showing the jointtherein; and Fig. 6 is a perspective View of a portion of one of the bucket ribs.

2 is a horizontal sheet steel 'cylinder 30 to 70 feet in length, as may be necessaif to provide the time of treatment require to suit the class of ores subjected to the cyanid leaching.` This cylinder has .its :feeding end 3 closed except for a central opening 4, and likewisehas its discharge end 5 closed except for the central opening 6. The cylinder 2 may bevprovided with a plurality of cylindricalguides? about its outside which rest vupon supporting and guidewheels 8 and upon which it may be rotated. It is immaterial how. the rotation may bel imparted to the cylinder, but I prefer to belt it with a worm wheel 9 whichengages a worm 11, the latter securedto a rotatable .shaft 12 `,driven byl a band pulley 13. The shaft is journaled in suitable bearings 10. By rotating the worm, the cylinder is caused to rotate slowly and with a steady motion which avoids excessive strains upon the long cylinder or upon its means of support.

n The ore or pulp associated with the cyanid `of potassium is deliveredinto a hopper 28 and, by a spout 29, is fed into the end of the cylinder through the opening 4. Thetreated product at the discharge end of the -cylinder is; delivered into the hopper 27 arranged within the opening and by it conveyed outside of the cylinder. The interior of the cylinder is provided with a helical inwardly directed ange 14, the pitch of the same being preferably about three feet so that with each revolution of the c'linder the bod of the pulp will be advance a distance o three feet. It 'is evident that, by reducing the pitch .of the helical flange, the

relative Arate of speed of travel of the pulp may be varied to suit the requirements ofthe ore to be treated. This helical fange -14 is best made in sections for commercial reasons in the manufacture; and as it is desir' able that the pul shall not flow throu h the joints 'so forme I prefer to provi e the abutting flange sections with a packed joint, the same to made in any suitable manner. In the particular;form ot, packed joint shown I provide -a radialA aperture formed between the abuttin ends of the sections and in said hole I p ace lead or other suitable packing 15". I do not'restrict myself in this respect as any for'mgof -reasonably tight joint may beemployed.

certain retarding effects produced' vupon theA feeding incident to the agitation and aeration process, as more fullylexplaincd later on.

The interior walls of the .cylinder are further provided with internal buckets 18 preferably formed by longitudinal ribs 1T extending between the helical flanges,4 the form or shape of these ribs being best understood from Figs. 3 and 6. These ribs are preferably arranged in an oblique angle to the interior wall of the cylinder to form the grooved pockets or buckets 1S (Fig. 3) and the inner edges of these ribs may have a T shaped construction formed by a flange 19, preferably with coarse serrations 2Ov at the' advancing' edge and finer serrations 21 at the trailing edge,(Fig. 6). These serrations cause the pulp to subdivide in overflowing from the buckets 18'and `to be caused to fall in spray or small streams and thereby become more thoroughly aerated and agitated. Y .I

'lhe inner wall of the cylinder 2 is preferably lined with cement as indicated :1t 22, preferably of about two to three inches in thickness and the ribs 17 project inwardly beyond the cement for about an equal amount.. These ribs may also be spaced from two or three inches apart, though for clearness I have shown them somewhat farther apart in the drawings. I also prefer the diameter of the cylinder to be about four feet and the depth of the helical flange to be about one footso as-to provide a central longitudinal clear passage 16 of between eighteen and twenty-four inches in diameter that there may be no lack of aeration to the whole treatment and also to provide for .easy access of workmen in-case of repairs.

It will be now understood that, according to the pitch of the helix, more or less of the dropping pulp from the buckets 18 will find.

its way back of the rear helical wall of any body of. the pulp, as will be more readily perceived by considering a'vertical'line from the right hand ends of any of the ascending buckets in Fig. 2, and this backward feeding or transference of the pulp acts as a retarding influence in the travei of the material through the 'cylinder and ina substantial las y .55 thefpulp passing measure increases the lix" viating treat-mentl 5 ormed'with the'compartment 24 containing the discharging buckets 26 for picking up the pulp and solution and delivering it to the `discharge hopper 27 as will be readily understood by reference to Figs. 1 and 4. In caserit-is desired to perform an amalgamating operation upon the'coarser values .of the vore-before being discharged fromfthe cyls inde;` the chamber 24 may be supplied `with mercury which may be received in annular tial iron ribs 28, the latter being between the buckets 26 and the shell of the cylinder. The heaviermetallic portions of the pulp will, by reason of their'greater specific gravity, pass downward into these grooves and be treated t0 amalgamation and in due timethe amalgam may bedrawn olf through a-nozzle 25, normally closed with a screw plug.

As' an example to show the great amount of treatment received by the pulp in passing through the lixiviat-ing cylinder the following figures are significant: The length of the; v cylinder being, say, fifty feet and the pitch of the spirals'threefeet, therewill be six;- teen Subdivisions or bodies of the, pulp si;- multaneouslypassing through the apparatus, each body o approximately 3000 /tol 45000 pounds. |The cylindermay make one to Iivile revolutions perminute, so that any of these bodies of pulp will be 10 to 16 minutes in passing through the machine due tothe heli'- cal propulsion; but as there is about onejf l third retardation,l for reasons already ex:- lained, the actual time'oft'reatment would -40 e from 13. to 22minutes. Moreover it evident that thefpnip may be returned forretreatment, if so desired, and'especiall so if thecylirder is speeded up, a result w 'chl would greatly increase the treatment tov aera,l

time. In -other words, assuming grooves formed between the circumfereigr.

tion Vand agitation `in a -given period ofi, a deinite ing, this operation may e carriedon in the same apparatus under different degrees of 50 effective; agitation and aeration,with a re- "sultant reduction in the size of pl'ant refquired. It isto be-understood that, if deindersmay be em vloyed in the-same plant,

im! the plant would not have to be built on the #side 'of a steep hill, a requirement which bit; `'entails 'considerable dii'culty in estab; lisbin'gjgood-,nulling operations within a reasonable outlay in cost. If the cylinders were on the same level, a small bucket wheel.`

sired, .two or more of these lixiviating cyl- 'l porous character and the gold 1n a very subom the discharge. of .one`

elevator or ordinary rotary circulating pump would suflice for the transference of the pulp from one cylinder to the next.

The supply of oxygen and ozone is secured for the cyanid solution andthe -agitation insured, .both in the body-of the pulp in the bottom ofthe cylinder and also in the sprayed pulp, by the presence of the bucket ribs '17, ,because vof their action as buckets,

spilling their contents from'bucket to bucket and through the air into the liquid mass be-v low, and because of. their action as paddles or rifies in passing down into, transversely through and then'upwardly out of the pulp which thoroughly agit-ates the same. Moreover by examining Fig. 3, it will be seen that the descending ribs'17 carry large bodies' of air down below the body of pulp and cause said air to bubble up through the same z during the agitation; and the serrated;

edges .20 'act to 'subdivide the said air to an eiiectiveV conditionsoas to provide in.

numerable bubbles. It will also be seen that as the confined' air is `conveyed below the pulp it is put under pressure and this insures amore intimate-contact with theV oyanid solution in the presence of the values to be dissolved thereby increasing thespeed of action. '-l

Further agitation, grinding and rubbing action, to assist inthe breaking of the bubbles or films of hydrogen gas which invariably develop and are ever present 'when gold and silver are attacked by cyanid solutions, may be had by the use of pebbles which can be placed in the cylinder with the P111 ockets or buckets18 and dropped into the uid below to cause a pronounced splash.

These pebbles may be used-over and over again too much-.worn to have the desired size.

ioo

and which will'be carried up with the Whil'eI 'have shown my cylinder with the l ribs 17 -andpockets 18, it is to be understood that.f sorne cases, I may dispense witlrsaid ribs or atleast with them actingv as pockets and' rely upon the agitation producednby suicient pebbles -in conjunction withv the pulp, the pebbles to be separated atithe discharge end by passing over, a grating and to -be used over again, repeatedlye My invention may be used-directly with v f crus e d ore when the same is of a sufficiently "-,divided condition, but ordinarily the ore `=wou1d be subjected to the pulverizing acland the pulp passing through a )10 to 12 imesh 'screen delivered to a Huntington;

as my invention is applicable for use at any tion. of a 'stamp battery in cyanid solution stage of a cyanid process where lixiviation or leaching is required in order to dissolve out the initial values.

Having now'described my invention what I claim as new and desire to secure by'Letters Patent is '1. In an apparatus. of the character described, the combination of a substantially horizontal cylinder having an inlet at one end and a discharge at the other end and also provided on its interior with a helical flangel secured to its interior side wall and of a depth less than' the radius of the -cylinder to provide a central passage through the same and divide the materials being treated into a plurality of separate bodies and also having a plurality of bucket de- A vices arranged upon its inner walls between vIl() the helical flanges for lifting and spilling the contents-beingrtreated, means to rot-ate the cylinder slowly, means for delivering materials to the inlet endofthe cylinder, and means for delivering the materials from the discharge end.

2; In an apparatus of theicharacter'def scribed, the combination of' a substantially horizontal cylinder having an 'inlet at 'one end and-'a discharge-at'the otherenaand also provided on its interior with a helicalflange securedto its interior-side wall and of a depth less than the radius of the cylinder to provide a central-'passage through the same and divide the materials being treated into a plurality of separatebodies and also 'having a plurality of longitudinal arallel inwardly directed ribs forming ucket devices arranged upon its inner walls between the helical flanges and vabutting thereupon for lifting and spilling the contents'being treated, v'means to rotate the cylinder slowly, means for delivering materials to the inlet endotthe cylinder,fa` cement lining to the interior ot the cylinder and forming fluid tight joints between" the' said cylinder and the helicalflange and said flange and the longitudinal parallel ribs,

and means for delivering the materials from the discharge end; v

3.- In an apparatus of the character described, the combination of a cylinder having an inlet at one end and a dischargeat the other end and also provided on its interior with a helical flange secured to its interior side wall and of a depth less than the radius of the cylinder to provide a central passage through the sameanda plurality of longitudinal inwardly directed ribs Y having serrated flanges' at their free edges and forming bucket devices" arranged upon its" innen walls between the hentai flanges 4for lifting and spilling the contents being treated, means to rotate the cylinder slowly, means` for delivering materials to the inlet end of 'the cylinder, and means fordelivere 55 ing the` materials from 'the discharge end.

4. In an apparatus of the character described, the' combination of-,a cylinder having an inlet'at one end and 'a discharge at the other end and also provided "on 'its finterior with a helicallange securedto its in'- terior side wall and of a depth lessthanthe -radius of the cylinder to provide 'a central- Vpassage tlirou l1 the same and a# plurality ot bucket devices arranged upon its inner walls between 'the helical tlangesfor lifting f5 and spilling. the contents being treated and also having an annular chamber adjacent 'to the; discharge endfor holding amalgamating mercury,im eans to rotate the cylinder slowly,'

means for delivering materials to the inlet 80- endjof the cylinder, and means for delivering the materialsfrom the discharge end.

I In an apparatus of thelcharacter described, a substantially horizontal rotatable with means to rotate the l.v

6. In an apparatus of the cliaracterxde- '95 scribed, a rotatable cylinder -hav-ing upon its. interior walls mcansfforelevating and t spilling the materials being treated to splash i the same and means to controlthespeedof I flow of the materials longitudinally through the cylinders, combined with a support, and means to rotate the cylinder. v7.*In an apparatus of the character de-l scribed, a rotatable substantially horizontal cylinder having upon its interiorv walls mfeans for elevating and spilling the materials being treated to'splash the -same and xrieans to mechanically propel the materials along the lower interior part of the cylinder and to control the flowof.v the materials longitudinally through the cylinder commensurate with the speed of rotation thereof, said means for elevating and spilling 'the materials subjecting the materfa "being :spilled to a' 'backward travel'du'ring the time 115 the material inthe bottom ofthe cylinder is l being given'a forward travel and said back- Wardl travel--being less than the 'forward trave i 8i In' an' apparatus of the character de- 120 scribed, a substantially horizontal rotatable-y 7 'cylinder having upon its interior walls means for elevating and spilling -thematerialsbeing treated to splash the'same `andf. means consisting of a deep helical flan e to 12.5

propel and produce a controlled ilow o the materials longitudinally'through the cyli-nder ahd in the path ofthe splash, combined with a support, and means to rotate the cylinder; i' 2 133 9. In an apparatus of 'the character described, a rotatable cylinder having an inlet at one end and an outlet lat the other and having. its interior provided with means to cause the materials to be treated to be passed in separate bodies longitudinally through the cylinder at a speed commensurate with the rotation thereof and also having its -in-,.

terior wall provided with longitudinal buckets for the dual purpose of raising and spilling the materials and feeding .it backward and for carrying the air down under the-materials within the lower part of the cylinder at frequent -intervals in each revolution of the cylinder and feeding it in advance of the spilled material acted upon by the same buckets, combined with means to rotate thecylinder'. a

10. In anapparatus of the character described, a rotatablecylinder having an inlet at one end and an outlet at the other and'A having its interior provided with means to cause the materials to be treated to be divided along tlie length of the cylinder into separate bodies and passed longitudinally at one end and an outlet at 4the other and' having its interior provided with means to cause the materials to be treated tobe positively passed lonfritudinally through the cylinder at a speed` commensurate with the rotation thereof and alsohaving its interior wall provided with buckets for carrying the air down under the materials within the lower part of the cylinder and the materials upward and spilling the same at. frequent intervals in each revolution of the cylinder the air being carried forward in advance of the materials spilled, combined .with a refractorylining -to the interior of the cylinder uponwhich the materials to betreated are supported.

12. In an apparatus of the character de# scribed,fa. horizontal rotatable cylinder having a longitudinal central passage and ar interior 'inwardly {,)rojecting helical guide fla-nge for separating the fluid contents into separate bodies and feeding "said bodies for'- ward, and means rotating witlithe cylinder to produce aeration by splashingthe said iiuid contents upon the separate bodies and transferring a `port-ion of each body to the' .next adjacent body with-each revolution of the cylinder, combined with means for rotating the cylinder slowly.

13. In an apparatus-,ofthe character de-l scribed, a horizontal rotatable cylinder having a longitudinal central passage vand anl interior inwardly. projecting helical guide flange for separating the fluidcontents into separate bodies and feeding it forward, and

means rotating with the cylinder to produce aeration by splashing the said fluid contents andvalso having an amalgamation chamber adjacent to the `discharge end of the cylin` der, combinedwith means for rotating the cylinder slowly, means for supplying materials to be treated to one end of the cylinder, and means for removing the treated materials from the otheror discharge end of the cylinder.

In testimony of which invention, I hereunto set my hand.-

W. L. IMLAY. Witnesses:

R.`M. KELLY, M. G. EGAN.

v 'Copies of this patent may be obtained for iive cents each, by addressing the Commissioner of Patenti,

. Washington, D. C. 

